Simulate an FMU

The Otfmi simulate function instanciates, initializes and simulates the FMU.

First, retrieve and load the FMU deviation.fmu.

import openturns as ot
import otfmi.example.utility
import matplotlib.pyplot as plt

path_fmu = otfmi.example.utility.get_path_fmu("deviation")
model = otfmi.fmi.load_fmu(path_fmu)

Note

model is a PyFMI object, loaded with Otfmi’s overlay.

As such, model.simulate() is a pure PyFMI method.

Use otfmi.fmi.simulate(model) to benefit from Otfmi’s overlay.

Otfmi simulate function notably eases initializing a FMU, see Initialize an FMU with non-default values.

On top of the initialization keywords, PyFMI simulation keywords can be employed:

result = otfmi.fmi.simulate(
    model,
    start_time=0,  # PyFMI keyword
    final_time=1,  # PyFMI keyword
    initialization_parameters=(["L"], [300]),
)  # Otfmi keyword
print("y = %g" % result.final("y"))

Simulation interval    : 0 - 1.0 seconds.
Elapsed simulation time: 0.015394541000006257 seconds.
y = 22.5

We can use these keyword to plot the deviation Y as function of the beam length L:

inputSample = ot.RegularGrid(1.0, 10.0, 10).getValues()

list_output = []
for length in inputSample:
    result = otfmi.fmi.simulate(model, initialization_parameters=(["L"], [length]))
    list_output.append(result.final("y"))
outputSample = ot.Sample([[xx] for xx in list_output])

plt.figure()
plt.plot(inputSample, outputSample)
plt.show()

Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.015109922999982928 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.014953440999988743 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01511776799998188 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.014916152000012062 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01504059300000904 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.0149757119999947 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.014943953999988935 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.015002902999981416 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.014923715999998421 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.015125951999976905 seconds.

The interest of the higher-level functions are:

- avoid the for loop on the points of the design of experiment,

- automatic formatting of the simulation outputs.